This is really a personal judgment call on how strong you want the matcha flavor in the cookie. Your taste will likely be different from someone else.

If I were trying to do this, I'd make a half-sized batch starting with one tablespoon of matcha. I could take the uncooked dough, but really you need to bake the cookies to understand what the final result will be like, then adjust according to your personal preference.

Here is a discussion about matcha and snickerdoodles. You can look at the original recipe from Bon Appetite and see the matcha quantities. The same amount may be just right for the roll out sugar cookies. It at least will give you a starting point. If you use the search function at the top of this page, you will find quite a few match a cookies.
http://www.bonappetit.com...